net/mac80211/ibss.c

   1 /*
   2  * IBSS mode implementation
   3  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
   4  * Copyright 2004, Instant802 Networks, Inc.
   5  * Copyright 2005, Devicescape Software, Inc.
   6  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   8  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/if_ether.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/rtnetlink.h>
  21 #include <net/mac80211.h>
  22 #include <asm/unaligned.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "rate.h"
  27
  28 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  29 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  30 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  31
  32 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  33 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  35
  36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  37
  38
  39 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  40                                         struct ieee80211_mgmt *mgmt,
  41                                         size_t len)
  42 {
  43         u16 auth_alg, auth_transaction, status_code;
  44
  45         if (len < 24 + 6)
  46                 return;
  47
  48         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  49         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  50         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  51
  52         /*
  53          * IEEE 802.11 standard does not require authentication in IBSS
  54          * networks and most implementations do not seem to use it.
  55          * However, try to reply to authentication attempts if someone
  56          * has actually implemented this.
  57          */
  58         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  59                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  60                                     sdata->u.ibss.bssid, NULL, 0, 0);
  61 }
  62
  63 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  64                                       const u8 *bssid, const int beacon_int,
  65                                       struct ieee80211_channel *chan,
  66                                       const u32 basic_rates,
  67                                       const u16 capability, u64 tsf)
  68 {
  69         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  70         struct ieee80211_local *local = sdata->local;
  71         int rates, i;
  72         struct sk_buff *skb;
  73         struct ieee80211_mgmt *mgmt;
  74         u8 *pos;
  75         struct ieee80211_supported_band *sband;
  76         struct cfg80211_bss *bss;
  77         u32 bss_change;
  78         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  79
  80         /* Reset own TSF to allow time synchronization work. */
  81         drv_reset_tsf(local);
  82
  83         skb = ifibss->skb;
  84         rcu_assign_pointer(ifibss->presp, NULL);
  85         synchronize_rcu();
  86         skb->data = skb->head;
  87         skb->len = 0;
  88         skb_reset_tail_pointer(skb);
  89         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  90
  91         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  92                 sta_info_flush(sdata->local, sdata);
  93
  94         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  95
  96         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  97
  98         local->oper_channel = chan;
  99         local->oper_channel_type = NL80211_CHAN_NO_HT;
 100         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 101
 102         sband = local->hw.wiphy->bands[chan->band];
 103
 104         /* build supported rates array */
 105         pos = supp_rates;
 106         for (i = 0; i < sband->n_bitrates; i++) {
 107                 int rate = sband->bitrates[i].bitrate;
 108                 u8 basic = 0;
 109                 if (basic_rates & BIT(i))
 110                         basic = 0x80;
 111                 *pos++ = basic | (u8) (rate / 5);
 112         }
 113
 114         /* Build IBSS probe response */
 115         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 116         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 117         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 118                                           IEEE80211_STYPE_PROBE_RESP);
 119         memset(mgmt->da, 0xff, ETH_ALEN);
 120         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 121         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 122         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 123         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 124         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 125
 126         pos = skb_put(skb, 2 + ifibss->ssid_len);
 127         *pos++ = WLAN_EID_SSID;
 128         *pos++ = ifibss->ssid_len;
 129         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 130
 131         rates = sband->n_bitrates;
 132         if (rates > 8)
 133                 rates = 8;
 134         pos = skb_put(skb, 2 + rates);
 135         *pos++ = WLAN_EID_SUPP_RATES;
 136         *pos++ = rates;
 137         memcpy(pos, supp_rates, rates);
 138
 139         if (sband->band == IEEE80211_BAND_2GHZ) {
 140                 pos = skb_put(skb, 2 + 1);
 141                 *pos++ = WLAN_EID_DS_PARAMS;
 142                 *pos++ = 1;
 143                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 144         }
 145
 146         pos = skb_put(skb, 2 + 2);
 147         *pos++ = WLAN_EID_IBSS_PARAMS;
 148         *pos++ = 2;
 149         /* FIX: set ATIM window based on scan results */
 150         *pos++ = 0;
 151         *pos++ = 0;
 152
 153         if (sband->n_bitrates > 8) {
 154                 rates = sband->n_bitrates - 8;
 155                 pos = skb_put(skb, 2 + rates);
 156                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 157                 *pos++ = rates;
 158                 memcpy(pos, &supp_rates[8], rates);
 159         }
 160
 161         if (ifibss->ie_len)
 162                 memcpy(skb_put(skb, ifibss->ie_len),
 163                        ifibss->ie, ifibss->ie_len);
 164
 165         rcu_assign_pointer(ifibss->presp, skb);
 166
 167         sdata->vif.bss_conf.beacon_int = beacon_int;
 168         bss_change = BSS_CHANGED_BEACON_INT;
 169         bss_change |= ieee80211_reset_erp_info(sdata);
 170         bss_change |= BSS_CHANGED_BSSID;
 171         bss_change |= BSS_CHANGED_BEACON;
 172         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 173         ieee80211_bss_info_change_notify(sdata, bss_change);
 174
 175         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 176
 177         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 178         mod_timer(&ifibss->timer,
 179                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 180
 181         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 182                                         mgmt, skb->len, 0, GFP_KERNEL);
 183         cfg80211_put_bss(bss);
 184         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 185 }
 186
 187 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 188                                     struct ieee80211_bss *bss)
 189 {
 190         struct ieee80211_supported_band *sband;
 191         u32 basic_rates;
 192         int i, j;
 193         u16 beacon_int = bss->cbss.beacon_interval;
 194
 195         if (beacon_int < 10)
 196                 beacon_int = 10;
 197
 198         sband = sdata->local->hw.wiphy->bands[bss->cbss.channel->band];
 199
 200         basic_rates = 0;
 201
 202         for (i = 0; i < bss->supp_rates_len; i++) {
 203                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 204                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 205
 206                 for (j = 0; j < sband->n_bitrates; j++) {
 207                         if (sband->bitrates[j].bitrate == rate) {
 208                                 if (is_basic)
 209                                         basic_rates |= BIT(j);
 210                                 break;
 211                         }
 212                 }
 213         }
 214
 215         __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid,
 216                                   beacon_int,
 217                                   bss->cbss.channel,
 218                                   basic_rates,
 219                                   bss->cbss.capability,
 220                                   bss->cbss.tsf);
 221 }
 222
 223 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 224                                   struct ieee80211_mgmt *mgmt,
 225                                   size_t len,
 226                                   struct ieee80211_rx_status *rx_status,
 227                                   struct ieee802_11_elems *elems,
 228                                   bool beacon)
 229 {
 230         struct ieee80211_local *local = sdata->local;
 231         int freq;
 232         struct ieee80211_bss *bss;
 233         struct sta_info *sta;
 234         struct ieee80211_channel *channel;
 235         u64 beacon_timestamp, rx_timestamp;
 236         u32 supp_rates = 0;
 237         enum ieee80211_band band = rx_status->band;
 238
 239         if (elems->ds_params && elems->ds_params_len == 1)
 240                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 241         else
 242                 freq = rx_status->freq;
 243
 244         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 245
 246         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 247                 return;
 248
 249         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 250             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 251                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 252
 253                 rcu_read_lock();
 254
 255                 sta = sta_info_get(sdata, mgmt->sa);
 256                 if (sta) {
 257                         u32 prev_rates;
 258
 259                         prev_rates = sta->sta.supp_rates[band];
 260                         /* make sure mandatory rates are always added */
 261                         sta->sta.supp_rates[band] = supp_rates |
 262                                 ieee80211_mandatory_rates(local, band);
 263
 264 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 265                         if (sta->sta.supp_rates[band] != prev_rates)
 266                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 267                                     "for %pM based on beacon info (0x%llx | "
 268                                     "0x%llx -> 0x%llx)\n",
 269                                     sdata->name,
 270                                     sta->sta.addr,
 271                                     (unsigned long long) prev_rates,
 272                                     (unsigned long long) supp_rates,
 273                                     (unsigned long long) sta->sta.supp_rates[band]);
 274 #endif
 275                 } else
 276                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 277
 278                 rcu_read_unlock();
 279         }
 280
 281         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 282                                         channel, beacon);
 283         if (!bss)
 284                 return;
 285
 286         /* was just updated in ieee80211_bss_info_update */
 287         beacon_timestamp = bss->cbss.tsf;
 288
 289         /* check if we need to merge IBSS */
 290
 291         /* merge only on beacons (???) */
 292         if (!beacon)
 293                 goto put_bss;
 294
 295         /* we use a fixed BSSID */
 296         if (sdata->u.ibss.bssid)
 297                 goto put_bss;
 298
 299         /* not an IBSS */
 300         if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS))
 301                 goto put_bss;
 302
 303         /* different channel */
 304         if (bss->cbss.channel != local->oper_channel)
 305                 goto put_bss;
 306
 307         /* different SSID */
 308         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 309             memcmp(elems->ssid, sdata->u.ibss.ssid,
 310                                 sdata->u.ibss.ssid_len))
 311                 goto put_bss;
 312
 313         /* same BSSID */
 314         if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 315                 goto put_bss;
 316
 317         if (rx_status->flag & RX_FLAG_TSFT) {
 318                 /*
 319                  * For correct IBSS merging we need mactime; since mactime is
 320                  * defined as the time the first data symbol of the frame hits
 321                  * the PHY, and the timestamp of the beacon is defined as "the
 322                  * time that the data symbol containing the first bit of the
 323                  * timestamp is transmitted to the PHY plus the transmitting
 324                  * STA's delays through its local PHY from the MAC-PHY
 325                  * interface to its interface with the WM" (802.11 11.1.2)
 326                  * - equals the time this bit arrives at the receiver - we have
 327                  * to take into account the offset between the two.
 328                  *
 329                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 330                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 331                  */
 332                 int rate;
 333
 334                 if (rx_status->flag & RX_FLAG_HT)
 335                         rate = 65; /* TODO: HT rates */
 336                 else
 337                         rate = local->hw.wiphy->bands[band]->
 338                                 bitrates[rx_status->rate_idx].bitrate;
 339
 340                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 341         } else {
 342                 /*
 343                  * second best option: get current TSF
 344                  * (will return -1 if not supported)
 345                  */
 346                 rx_timestamp = drv_get_tsf(local);
 347         }
 348
 349 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 350         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 351                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 352                mgmt->sa, mgmt->bssid,
 353                (unsigned long long)rx_timestamp,
 354                (unsigned long long)beacon_timestamp,
 355                (unsigned long long)(rx_timestamp - beacon_timestamp),
 356                jiffies);
 357 #endif
 358
 359         /* give slow hardware some time to do the TSF sync */
 360         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 361                 goto put_bss;
 362
 363         if (beacon_timestamp > rx_timestamp) {
 364 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 365                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 366                        "local TSF - IBSS merge with BSSID %pM\n",
 367                        sdata->name, mgmt->bssid);
 368 #endif
 369                 ieee80211_sta_join_ibss(sdata, bss);
 370                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 371         }
 372
 373  put_bss:
 374         ieee80211_rx_bss_put(local, bss);
 375 }
 376
 377 /*
 378  * Add a new IBSS station, will also be called by the RX code when,
 379  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 380  * must be callable in atomic context.
 381  */
 382 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 383                                         u8 *bssid,u8 *addr, u32 supp_rates)
 384 {
 385         struct ieee80211_local *local = sdata->local;
 386         struct sta_info *sta;
 387         int band = local->hw.conf.channel->band;
 388
 389         /*
 390          * XXX: Consider removing the least recently used entry and
 391          *      allow new one to be added.
 392          */
 393         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 394                 if (net_ratelimit())
 395                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 396                                sdata->name, addr);
 397                 return NULL;
 398         }
 399
 400         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 401                 return NULL;
 402
 403 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 404         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 405                wiphy_name(local->hw.wiphy), addr, sdata->name);
 406 #endif
 407
 408         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 409         if (!sta)
 410                 return NULL;
 411
 412         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 413
 414         /* make sure mandatory rates are always added */
 415         sta->sta.supp_rates[band] = supp_rates |
 416                         ieee80211_mandatory_rates(local, band);
 417
 418         rate_control_rate_init(sta);
 419
 420         if (sta_info_insert(sta))
 421                 return NULL;
 422
 423         return sta;
 424 }
 425
 426 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 427 {
 428         struct ieee80211_local *local = sdata->local;
 429         int active = 0;
 430         struct sta_info *sta;
 431
 432         rcu_read_lock();
 433
 434         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 435                 if (sta->sdata == sdata &&
 436                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 437                                jiffies)) {
 438                         active++;
 439                         break;
 440                 }
 441         }
 442
 443         rcu_read_unlock();
 444
 445         return active;
 446 }
 447
 448
 449 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 450 {
 451         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 452
 453         mod_timer(&ifibss->timer,
 454                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 455
 456         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 457
 458         if (time_before(jiffies, ifibss->last_scan_completed +
 459                        IEEE80211_IBSS_MERGE_INTERVAL))
 460                 return;
 461
 462         if (ieee80211_sta_active_ibss(sdata))
 463                 return;
 464
 465         if (ifibss->fixed_channel)
 466                 return;
 467
 468         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 469                "IBSS networks with same SSID (merge)\n", sdata->name);
 470
 471         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 472 }
 473
 474 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 475 {
 476         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 477         struct ieee80211_local *local = sdata->local;
 478         struct ieee80211_supported_band *sband;
 479         u8 bssid[ETH_ALEN];
 480         u16 capability;
 481         int i;
 482
 483         if (ifibss->fixed_bssid) {
 484                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 485         } else {
 486                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 487                  * own MAC address to make sure that devices that do not have proper
 488                  * random number generator get different BSSID. */
 489                 get_random_bytes(bssid, ETH_ALEN);
 490                 for (i = 0; i < ETH_ALEN; i++)
 491                         bssid[i] ^= sdata->vif.addr[i];
 492                 bssid[0] &= ~0x01;
 493                 bssid[0] |= 0x02;
 494         }
 495
 496         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 497                sdata->name, bssid);
 498
 499         sband = local->hw.wiphy->bands[ifibss->channel->band];
 500
 501         capability = WLAN_CAPABILITY_IBSS;
 502
 503         if (ifibss->privacy)
 504                 capability |= WLAN_CAPABILITY_PRIVACY;
 505         else
 506                 sdata->drop_unencrypted = 0;
 507
 508         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 509                                   ifibss->channel, 3, /* first two are basic */
 510                                   capability, 0);
 511 }
 512
 513 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 514 {
 515         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 516         struct ieee80211_local *local = sdata->local;
 517         struct ieee80211_bss *bss;
 518         struct ieee80211_channel *chan = NULL;
 519         const u8 *bssid = NULL;
 520         int active_ibss;
 521         u16 capability;
 522
 523         active_ibss = ieee80211_sta_active_ibss(sdata);
 524 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 525         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 526                sdata->name, active_ibss);
 527 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 528
 529         if (active_ibss)
 530                 return;
 531
 532         capability = WLAN_CAPABILITY_IBSS;
 533         if (ifibss->privacy)
 534                 capability |= WLAN_CAPABILITY_PRIVACY;
 535         if (ifibss->fixed_bssid)
 536                 bssid = ifibss->bssid;
 537         if (ifibss->fixed_channel)
 538                 chan = ifibss->channel;
 539         if (!is_zero_ether_addr(ifibss->bssid))
 540                 bssid = ifibss->bssid;
 541         bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 542                                        ifibss->ssid, ifibss->ssid_len,
 543                                        WLAN_CAPABILITY_IBSS |
 544                                        WLAN_CAPABILITY_PRIVACY,
 545                                        capability);
 546
 547         if (bss) {
 548 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 549                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 550                        "%pM\n", bss->cbss.bssid, ifibss->bssid);
 551 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 552
 553                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 554                        " based on configured SSID\n",
 555                        sdata->name, bss->cbss.bssid);
 556
 557                 ieee80211_sta_join_ibss(sdata, bss);
 558                 ieee80211_rx_bss_put(local, bss);
 559                 return;
 560         }
 561
 562 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 563         printk(KERN_DEBUG "   did not try to join ibss\n");
 564 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 565
 566         /* Selected IBSS not found in current scan results - try to scan */
 567         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
 568             !ieee80211_sta_active_ibss(sdata)) {
 569                 mod_timer(&ifibss->timer,
 570                           round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 571         } else if (time_after(jiffies, ifibss->last_scan_completed +
 572                                         IEEE80211_SCAN_INTERVAL)) {
 573                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 574                        "join\n", sdata->name);
 575
 576                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 577                                                 ifibss->ssid_len);
 578         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
 579                 int interval = IEEE80211_SCAN_INTERVAL;
 580
 581                 if (time_after(jiffies, ifibss->ibss_join_req +
 582                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 583                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 584                                 ieee80211_sta_create_ibss(sdata);
 585                                 return;
 586                         }
 587                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 588                                " %d MHz\n", sdata->name,
 589                                local->hw.conf.channel->center_freq);
 590
 591                         /* No IBSS found - decrease scan interval and continue
 592                          * scanning. */
 593                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 594                 }
 595
 596                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 597                 mod_timer(&ifibss->timer,
 598                           round_jiffies(jiffies + interval));
 599         }
 600 }
 601
 602 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 603                                         struct ieee80211_mgmt *mgmt,
 604                                         size_t len)
 605 {
 606         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 607         struct ieee80211_local *local = sdata->local;
 608         int tx_last_beacon;
 609         struct sk_buff *skb;
 610         struct ieee80211_mgmt *resp;
 611         u8 *pos, *end;
 612
 613         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 614             len < 24 + 2 || !ifibss->presp)
 615                 return;
 616
 617         tx_last_beacon = drv_tx_last_beacon(local);
 618
 619 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 620         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 621                " (tx_last_beacon=%d)\n",
 622                sdata->name, mgmt->sa, mgmt->da,
 623                mgmt->bssid, tx_last_beacon);
 624 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 625
 626         if (!tx_last_beacon)
 627                 return;
 628
 629         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 630             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 631                 return;
 632
 633         end = ((u8 *) mgmt) + len;
 634         pos = mgmt->u.probe_req.variable;
 635         if (pos[0] != WLAN_EID_SSID ||
 636             pos + 2 + pos[1] > end) {
 637 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 638                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 639                        "from %pM\n",
 640                        sdata->name, mgmt->sa);
 641 #endif
 642                 return;
 643         }
 644         if (pos[1] != 0 &&
 645             (pos[1] != ifibss->ssid_len ||
 646              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 647                 /* Ignore ProbeReq for foreign SSID */
 648                 return;
 649         }
 650
 651         /* Reply with ProbeResp */
 652         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 653         if (!skb)
 654                 return;
 655
 656         resp = (struct ieee80211_mgmt *) skb->data;
 657         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 658 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 659         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 660                sdata->name, resp->da);
 661 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 662         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 663         ieee80211_tx_skb(sdata, skb);
 664 }
 665
 666 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 667                                          struct ieee80211_mgmt *mgmt,
 668                                          size_t len,
 669                                          struct ieee80211_rx_status *rx_status)
 670 {
 671         size_t baselen;
 672         struct ieee802_11_elems elems;
 673
 674         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 675                 return; /* ignore ProbeResp to foreign address */
 676
 677         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 678         if (baselen > len)
 679                 return;
 680
 681         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 682                                 &elems);
 683
 684         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 685 }
 686
 687 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 688                                      struct ieee80211_mgmt *mgmt,
 689                                      size_t len,
 690                                      struct ieee80211_rx_status *rx_status)
 691 {
 692         size_t baselen;
 693         struct ieee802_11_elems elems;
 694
 695         /* Process beacon from the current BSS */
 696         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 697         if (baselen > len)
 698                 return;
 699
 700         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 701
 702         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 703 }
 704
 705 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 706                                           struct sk_buff *skb)
 707 {
 708         struct ieee80211_rx_status *rx_status;
 709         struct ieee80211_mgmt *mgmt;
 710         u16 fc;
 711
 712         rx_status = IEEE80211_SKB_RXCB(skb);
 713         mgmt = (struct ieee80211_mgmt *) skb->data;
 714         fc = le16_to_cpu(mgmt->frame_control);
 715
 716         switch (fc & IEEE80211_FCTL_STYPE) {
 717         case IEEE80211_STYPE_PROBE_REQ:
 718                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 719                 break;
 720         case IEEE80211_STYPE_PROBE_RESP:
 721                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 722                                              rx_status);
 723                 break;
 724         case IEEE80211_STYPE_BEACON:
 725                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 726                                          rx_status);
 727                 break;
 728         case IEEE80211_STYPE_AUTH:
 729                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 730                 break;
 731         }
 732
 733         kfree_skb(skb);
 734 }
 735
 736 static void ieee80211_ibss_work(struct work_struct *work)
 737 {
 738         struct ieee80211_sub_if_data *sdata =
 739                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 740         struct ieee80211_local *local = sdata->local;
 741         struct ieee80211_if_ibss *ifibss;
 742         struct sk_buff *skb;
 743
 744         if (WARN_ON(local->suspended))
 745                 return;
 746
 747         if (!netif_running(sdata->dev))
 748                 return;
 749
 750         if (local->scanning)
 751                 return;
 752
 753         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 754                 return;
 755         ifibss = &sdata->u.ibss;
 756
 757         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 758                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 759
 760         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 761                 return;
 762
 763         switch (ifibss->state) {
 764         case IEEE80211_IBSS_MLME_SEARCH:
 765                 ieee80211_sta_find_ibss(sdata);
 766                 break;
 767         case IEEE80211_IBSS_MLME_JOINED:
 768                 ieee80211_sta_merge_ibss(sdata);
 769                 break;
 770         default:
 771                 WARN_ON(1);
 772                 break;
 773         }
 774 }
 775
 776 static void ieee80211_ibss_timer(unsigned long data)
 777 {
 778         struct ieee80211_sub_if_data *sdata =
 779                 (struct ieee80211_sub_if_data *) data;
 780         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 781         struct ieee80211_local *local = sdata->local;
 782
 783         if (local->quiescing) {
 784                 ifibss->timer_running = true;
 785                 return;
 786         }
 787
 788         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 789         ieee80211_queue_work(&local->hw, &ifibss->work);
 790 }
 791
 792 #ifdef CONFIG_PM
 793 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 794 {
 795         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 796
 797         cancel_work_sync(&ifibss->work);
 798         if (del_timer_sync(&ifibss->timer))
 799                 ifibss->timer_running = true;
 800 }
 801
 802 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 803 {
 804         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 805
 806         if (ifibss->timer_running) {
 807                 add_timer(&ifibss->timer);
 808                 ifibss->timer_running = false;
 809         }
 810 }
 811 #endif
 812
 813 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 814 {
 815         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 816
 817         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 818         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 819                     (unsigned long) sdata);
 820         skb_queue_head_init(&ifibss->skb_queue);
 821 }
 822
 823 /* scan finished notification */
 824 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 825 {
 826         struct ieee80211_sub_if_data *sdata;
 827
 828         mutex_lock(&local->iflist_mtx);
 829         list_for_each_entry(sdata, &local->interfaces, list) {
 830                 if (!netif_running(sdata->dev))
 831                         continue;
 832                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 833                         continue;
 834                 if (!sdata->u.ibss.ssid_len)
 835                         continue;
 836                 sdata->u.ibss.last_scan_completed = jiffies;
 837                 mod_timer(&sdata->u.ibss.timer, 0);
 838         }
 839         mutex_unlock(&local->iflist_mtx);
 840 }
 841
 842 ieee80211_rx_result
 843 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 844 {
 845         struct ieee80211_local *local = sdata->local;
 846         struct ieee80211_mgmt *mgmt;
 847         u16 fc;
 848
 849         if (skb->len < 24)
 850                 return RX_DROP_MONITOR;
 851
 852         mgmt = (struct ieee80211_mgmt *) skb->data;
 853         fc = le16_to_cpu(mgmt->frame_control);
 854
 855         switch (fc & IEEE80211_FCTL_STYPE) {
 856         case IEEE80211_STYPE_PROBE_RESP:
 857         case IEEE80211_STYPE_BEACON:
 858         case IEEE80211_STYPE_PROBE_REQ:
 859         case IEEE80211_STYPE_AUTH:
 860                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 861                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
 862                 return RX_QUEUED;
 863         }
 864
 865         return RX_DROP_MONITOR;
 866 }
 867
 868 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 869                         struct cfg80211_ibss_params *params)
 870 {
 871         struct sk_buff *skb;
 872
 873         if (params->bssid) {
 874                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 875                 sdata->u.ibss.fixed_bssid = true;
 876         } else
 877                 sdata->u.ibss.fixed_bssid = false;
 878
 879         sdata->u.ibss.privacy = params->privacy;
 880
 881         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 882
 883         sdata->u.ibss.channel = params->channel;
 884         sdata->u.ibss.fixed_channel = params->channel_fixed;
 885
 886         if (params->ie) {
 887                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 888                                            GFP_KERNEL);
 889                 if (sdata->u.ibss.ie)
 890                         sdata->u.ibss.ie_len = params->ie_len;
 891         }
 892
 893         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 894                             36 /* bitrates */ +
 895                             34 /* SSID */ +
 896                             3  /* DS params */ +
 897                             4  /* IBSS params */ +
 898                             params->ie_len);
 899         if (!skb)
 900                 return -ENOMEM;
 901
 902         sdata->u.ibss.skb = skb;
 903         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 904         sdata->u.ibss.ibss_join_req = jiffies;
 905
 906         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 907
 908         /*
 909          * The ssid_len setting below is used to see whether
 910          * we are active, and we need all other settings
 911          * before that may get visible.
 912          */
 913         mb();
 914
 915         sdata->u.ibss.ssid_len = params->ssid_len;
 916
 917         ieee80211_recalc_idle(sdata->local);
 918
 919         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 920         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
 921
 922         return 0;
 923 }
 924
 925 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 926 {
 927         struct sk_buff *skb;
 928
 929         del_timer_sync(&sdata->u.ibss.timer);
 930         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 931         cancel_work_sync(&sdata->u.ibss.work);
 932         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 933
 934         sta_info_flush(sdata->local, sdata);
 935
 936         /* remove beacon */
 937         kfree(sdata->u.ibss.ie);
 938         skb = sdata->u.ibss.presp;
 939         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 940         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 941         synchronize_rcu();
 942         kfree_skb(skb);
 943
 944         skb_queue_purge(&sdata->u.ibss.skb_queue);
 945         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 946         sdata->u.ibss.ssid_len = 0;
 947
 948         ieee80211_recalc_idle(sdata->local);
 949
 950         return 0;
 951 }